FIG. 10 is a schematic block diagram of an example known vehicle including a power transfer unit. Vehicle V includes engine EN, transmission T, front differential gear FDG, front wheels FW, power transfer unit PTU, rear differential gear RDG, and rear wheels RW. Vehicle V is a front-wheel drive vehicle, that is, when vehicle V is in operation and power is being delivered from the engine to the transmission, torque is always transmitted to the front wheels via gear FDG to move vehicle V. However, power flow to wheels RW via gear RDG is controlled by unit PTU. That is, PTU can connect or disconnect gear RDG from gear FDG.